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Tristate Logic - Increasing current drive

  1. Feb 7, 2013 #1
    I am currently looking at charlieplexing that can in theory cause me to be able to control eight 7 segment displays using 8 microcontroller pins, however in practice there is not enough current to drive all the displays. What I need is to increase the current drive from the microcontroller,

    The information that I can give you is that I plan on using "KINGBRIGHT ELECTRONIC SC15-11SRWA" 7 segment displays. From what I understand is that it requires around 30 mA per segment on the display. The microcontroller I am currently using (will probably upgrade to one with more I/O pins) is a PIC16f84a, which I believe drives 25mA per pin.

    I appreciate any help anybody can give me. Thanks.
  2. jcsd
  3. Feb 7, 2013 #2


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    Staff: Mentor

    Just use '245 type drivers to boost the current.
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